Gas burner with automatically-controlled safety valve



Oct.` 9, 192s. 1,687,358y

H. BACH GAS BURNER WI'VIH AUTOMATICALLY CONTROLLED SAFETY VALVE FiledApril 29, '1927' Patented ct. 9, 192,8.

HENRIK BACH, OF DISIOSANMARTIN, TRAIN'SYLVANILA, RUMANIA.k

GAS BURNER WITH AUTOMATICALLY-CONTROLLED SAFETY VALVE.

Application 1ed April 29, 1927. Serial No. 187,610.

This invention relates to gas burners with safety device automaticallycontrolled by the flame of the burner.

'lhe object of this invention is to provide a safety gas burner forindustrial and domestic gas appliances, which is so constructed that ifthe llame of the burner should ever gol l out for any reason,

the gas supply to the burner is automatically shut oil'. ltI will beappreciated that in domestic stoves or in industrial furnaces the flameof the burner sometimes goes out in consequence of freezing ofregulators, or sudden drop of the gas pressure, of strong draughtthrough the chimney and other reasons. Consequently when the cause ofthe sudden shut oil' is eliminated and the gas again iiows unchecked tothe burner and discharges freely in the stove or furnace, or even in theroom without being ignited, the stove, furnace or room will be lilledwith explosive gas mixture which not infrequently results in explosion.

By means'of this invention, the gas burner ill be immediately andautomatically shut oll' it' the flame of the burner blows out andprevents the uncontrolled flowing out of the fuel. The working of thissafety device is absolutely sure as its principle is based on commonphysical law, i. e. the expansion of metals under the change oftemperature.

This safety gas burner is appliable to any form or size of apparatus,stove, lamps, furnaces, boilers, etc.

The accompanying drawing is a longitudinal section of a burner embodyingmy invention.

The device consists of a tubular casing l substantiallyA one half ofWhich constitutes a burner head 2 to be placed in the stove or furnace.One end of the casing is threaded for connection to the gas supply pipeor main by an ordinary valve coupling not shown. The burner head portion2 has a series of longitudinal slots 3 therein constituting flameoriices behind which is mounted a plate 4 forming a combustion chamber 5into which gas mixed with air from the tube 1 enters throughperforations 6 in said plate.

A thermostatic member 7 consisting of' a length of nickel wire isclamped at one end between screws 8 in the head 9 ofthe casing, andextends centrally through the combustion chamber 5 and through the endwall of the latter into the casing.

The threaded end of the casing 1 which is to be connected to the gasmain, contains a concentrically mounted valve chamber 10 formed with aninternal annular flange ll constituting al seat for a valve 12, carriedby a valve stem 13 slidable and axially mounted in the inner end 14 ofvalve chamber 10. ln the outer end of the latter is mounted a plate lllhaving a series of apertures l5 for the advmissionfof gas from the gasmain imo the valve chamber 10, and projecting axially through the plate14 is a pin '1U forming a'n extension of the valve stem 13 on theunderside of the valve. Surrounding the pin LU between the plate 14 andvalve 12 is a coiled spring 17 adapted to yieldingly hold the valve 12on its seat l1.

ln the inner end of the valve chamber. 10 near the periphery of thelatter is mounted a gas discharge nozzle 18 and adjacent the latter inthe wall of the casing 1 .is formed a large air inlet opening 19 forsupplying outside airto the gas as it leaves the nozzle 18.

On the inner end ot' the valve stem l13 is mounted an arm 2() whichextends laterally through a longitudinal slot in thefcasing 1. Said armcarries a slide plate 21 which covers the slot and has a knob 22 on itsouter end.v By moving the knob in the direction of the arrow said armoperates to depress the stein 13 against the action of spring 17 therebyunseating the valve 12 allowing gas to be discharged through nozzle 18into the casing 1, where the gas mixes with air entering aperture 19 andflows into the combustion chamloer 5 through the apertun-s 6 and isignited.

Flames which issue through the slots 3 also heat the expansible member 7The movable end 23 of the member 7 is pivotally connected.

to the short arm 24 of a bell-crank lever which is pivoted on a bracket25 secured inside the casing 1.

The long arm 26 of the bell-crank lever extends through and is movablein an aperture 27 formed inthe lateral arm 2() and the free end of saidarm 26 has a hook 28 formed thereon adapted to engage a notch 29 formedin the side of the valve stem 13.

A spring 30 surrounding the pivot of the bell-crank lever has one endbearing on the bracket 25 while the other end is held tensioned againstthe long arm 26 of the lever so that the latter has a tendency to moveits hooked end'28 towards the' valve stem 13.

After the valve 12 has been moved from its seat as described above, andthe gas in the combustion chamber is ignited, it is necessary to holdthe valve in open position for only a very short while, about thirtyseconds, for as soon as the member 7 becomes heated it expandslongitudinally and allows the spring 30 to function thereby shifting thelong-arm 26 of the lever to the left from the position shown in thedrawing until the hook 28 engages the notch 29 and holds the stem 13depressed.

The spring 30 is not essential to the operation above described as theexpansion of member 7 will through the connection of the latter with theshort arm 24 cause the long arm to swing into locking position with thespindle.

Should the burner become extinguished for any reason, the member 7 willquickly cool and contract causing the levers to swing in the oppositedirection thereby withdrawing the hook 28 from notch 29 releasing thespindle so that the valve 12 will be seated by the spring 17 thusshutting off the supply of gas through nozzle 18.

I claim- 1. A gas burner comprising a tubular casing for connection to agas supply pipe and having flame orifices and an air inlet, a combustionchamber formed in said casing behind the orifices, a gas supply nozzleopening into said casing adjacent the inlet, a spring urged valve havinga stem and conf trolling the admission of gas to the nozzle, means tomanually operate the valve, a .thermostatic 'member fixed at one end inthe Casing and extending through the combustion chamber, a bell-cranklever pivoted in the casing having a short arm pivoted to the movableend of the thermostatic member and a long arm extending longitudinallyofthe casing adapted to be moved automatically into and out of lockingengagement with the stem 0f the valve by the expansion and contractionrespectively of the thermostatic member.

2. A gas burner comprising a tubular housing, for connection to a gassupply pipe and having fiame orifices and an air inlet, a combustionchamber formed in the housin behind the orifices, a valve casing in theousing, a valve in the casing controlling an outlet port formed inthelatter, a stem carrying the valve arranged axially of the casingreciprocally mounted therein, a notch formed in the valve stem outsidethe casing, a gas supply nozzle communicating, with the housing andcasing above the valve, a slide outside the housing connected with thevalve stem, a spring in the valve casing normally closing the valve, abell-crank lever pivoted in the housing having one arm extendinglongitudinally of the latter and having a hooked end adapted to engagethe notch in the valve stem, and a thermostatic wire fixed in thehousing at one end and extending through the combustion chamber andhaving its movable end pivotally connected to the short arm of saidlever.

In testimony whereof I have signed my name to this specification.

HENRIK BACH.

